3D hierarchical SnO2@Ni(OH)2 core–shell nanowire arrays on carbon cloth for energy storage application

Abstract

A judicious combination of conducting materials with selected transition metal hydroxides to form core–shell nanostructures has attracted great attention owing to the underlying synergistic effect for energy storage. In this work, we fabricate a novel 3D nanostructure consisting of Ni(OH)₂ ultrathin nanoflakes directly anchored on SnO₂ nanowire arrays by a facile solution-based method, which utilizes the higher conductance of SnO₂ nanowires as the supporting scaffold to deposit Ni(OH)₂ for supercapacitor electrodes. Cyclic voltammetry and galvanostatic charge–discharge methods have been conducted to understand the capacitive performance of the SnO₂/Ni(OH)₂ core–shell nanocomposites. A specific capacitance of as high as 1553 F g⁻¹ is achieved at 0.5 A g⁻¹ in 6 M KOH aqueous solution. At a large current density of 10 A g⁻¹, the electrode retains a high capacitance value of 934 F g⁻¹. The superior capacitive behavior suggests that the hierarchical SnO₂@Ni(OH)₂ hybrid nanostructure is a very promising electrode material for fabricating high-performance supercapacitors.